An apparatus for cleaning an electrostatic reticle holder used in a lithography system includes a chamber for providing a low pressure environment for the electrostatic reticle holder and an ultrasound transducer configured to apply ultrasound waves to the electrostatic reticle holder. The apparatus further includes a controller configured to control the ultrasound transducer and a gas flow controller. The gas flow controller is configured to enable pressurizing or depressurizing the chamber.